Medical device delivery system including a resistance member

ABSTRACT

Example medical device delivery systems are disclosed. An example delivery system for an implantable medical device includes an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween. The delivery system also includes a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing. The delivery system also includes a selector coupled to the handle and a resistance member disposed along a portion of the selector. Further, the selector is configured to shift between a first configuration and a deployment configuration. Additionally, the carriage is free from the resistance member in the first configuration and the resistance member contacts the carriage in the deployment configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application Ser. No. 62/777,487, filed Dec. 10, 2018, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure pertains to medical devices, and methods for manufacturing medical devices. More particularly, the present disclosure pertains to medical device delivery systems including a translating engagement member.

BACKGROUND

A wide variety of intracorporeal medical devices have been developed for medical use, for example, intravascular use. Some of these devices include guidewires, catheters, and the like. These devices are manufactured by any one of a variety of different manufacturing methods and may be used according to any one of a variety of methods. Of the known medical devices and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices as well as alternative methods for manufacturing and using medical devices.

BRIEF SUMMARY

This disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An example delivery system for an implantable medical device includes an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween. The delivery system also includes a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing. The delivery system also includes a selector which may be in the form of a cap coupled to the handle and a resistance member disposed along a portion of the selector. Further, the selector is configured to shift between a first configuration and deployment configuration. Additionally, the carriage is free from the resistance member in the first configuration and the resistance member contacts the carriage in the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the resistance member contacts an inner surface along a distal end region of the housing in the first configuration.

Alternatively or additionally to any of the embodiments above, wherein the resistance member contacts an inner surface along a distal end region of the carriage in the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the carriage is configured to rotate, and wherein the resistance member is configured to increase a rotational force required to rotate the carriage in the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the cap includes a circumferential groove positioned along a proximal end region thereof, wherein at least a portion of the resistance member is positioned along the groove.

Alternatively or additionally to any of the embodiments above, further comprising an implant loading device positioned adjacent the distal end region of the outer shaft.

Alternatively or additionally to any of the embodiments above, wherein the cap includes an inner surface, an outer surface and a wall extending therebetween, and wherein the cap includes an aperture extending through a wall of the cap.

Alternatively or additionally to any of the embodiments above, wherein the aperture includes a length, and wherein the length of the aperture corresponds to a distance along which the cap shifts between the first configuration and the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the aperture is aligned along a longitudinal axis of the cap.

Alternatively or additionally to any of the embodiments above, wherein the aperture is offset from a longitudinal axis of the cap.

Alternatively or additionally to any of the embodiments above, wherein rotating the cap shifts it between the first configuration and the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the cap includes a circumferential lip extending circumferentially along a distal end region thereof.

Alternatively or additionally to any of the embodiments above, wherein the lip extends radially away from an outer surface of the cap.

Alternatively or additionally to any of the embodiments above, wherein the resistance member is configured to exert a radially outward force on an inner surface of the carriage in the deployment configuration.

Another example delivery system for an implantable medical device includes:

an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween;

a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing;

a cap coupled to the handle; and

a resistance member disposed along a portion of the cap;

wherein the cap is configured to shift between a first configuration and a deployment configuration, and wherein the carriage is free from the resistance member in the first configuration and wherein the resistance member exerts a radially outward force upon the carriage in the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the resistance member contacts an inner surface along a distal end region of the housing in the first configuration.

Alternatively or additionally to any of the embodiments above, wherein the resistance member contacts an inner surface along a distal end region of the carriage in the deployment configuration.

Alternatively or additionally to any of the embodiments above, wherein the carriage is configured to rotate, and wherein the resistance member is configured to increase a rotational force required to rotate the carriage in the deployment configuration.

An example method of manufacturing an implantable medical device includes:

-   -   engaging the implantable medical device with a medical device         delivery system in a pre-deployment configuration, the medical         device delivery system including: an outer shaft having a distal         end region, a proximal end region and a lumen extending         therebetween;     -   a handle coupled to the proximal end region of the outer shaft,         wherein the handle includes a first actuator, a carriage and a         housing;     -   a cap coupled to the handle; and     -   a resistance member disposed along a portion of the cap;     -   converting the medical device delivery system from a         pre-deployment configuration to a deployment configuration,         wherein converting the medical device delivery system includes         shifting the cap from a first position to a second position,         wherein the carriage is free from the resistance member when the         cap is in the first position and wherein the resistance member         contacts the carriage when the cap is in the second position.

Alternatively or additionally to any of the embodiments above, wherein the implantable medical device includes an implantable heart valve.

The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures, and Detailed Description, which follow, more particularly exemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which:

FIG. 1 illustrates an example medical device delivery system;

FIG. 2 illustrates an example step in the deployment of the example medical device shown in FIG. 1;

FIG. 3 illustrates another example step in the deployment of the example medical device shown in FIG. 1;

FIG. 4 illustrates a portion of the medical device system shown in FIGS. 1-3;

FIG. 5 is a cross-sectional view of an example handle of the medical device system shown in FIG. 1;

FIG. 6 is a perspective view of an example component of the medical device delivery system shown in FIG. 1;

FIG. 7 is a cross-sectional view of the example component of the medical device system shown in FIG. 5;

FIG. 8 is a cross-sectional view of a portion of the example handle shown in FIG. 1;

FIG. 9 is a cross-sectional view of a portion of the example handle shown in FIG. 1;

FIG. 10 is a perspective view of another example component of the medical device delivery system shown in FIG. 1;

FIG. 11 is a perspective view of an example stent loading device;

FIG. 12 is an exploded view of the example stent loading device shown in FIG. 11;

FIG. 13 is a cross-sectional view of the example stent loading device shown in FIG. 11.

While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the terms “about” may include numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “an embodiment”, “some embodiments”, “other embodiments”, etc., indicate that the embodiment described may include one or more particular features, structures, and/or characteristics. However, such recitations do not necessarily mean that all embodiments include the particular features, structures, and/or characteristics. Additionally, when particular features, structures, and/or characteristics are described in connection with one embodiment, it should be understood that such features, structures, and/or characteristics may also be used connection with other embodiments whether or not explicitly described unless clearly stated to the contrary.

The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

Diseases and/or medical conditions that impact the cardiovascular system are prevalent throughout the world. Traditionally, treatment of the cardiovascular system was often conducted by directly accessing the impacted part of the system. For example, treatment of a blockage in one or more of the coronary arteries was traditionally treated using coronary artery bypass surgery. As can be readily appreciated, such therapies are rather invasive to the patient and require significant recovery times and/or treatments. More recently, less invasive therapies have been developed, for example, where a blocked coronary artery could be accessed and treated via a percutaneous catheter (e.g., angioplasty). Such therapies have gained wide acceptance among patients and clinicians.

Some relatively common medical conditions may include or be the result of inefficiency, ineffectiveness, or complete failure of one or more of the valves within the heart. For example, failure of the aortic valve or the mitral valve can have a serious effect on a human and could lead to serious health conditions and/or death if not dealt with properly. Treatment of defective heart valves poses other challenges in that the treatment often requires the repair or outright replacement of the defective valve. Such therapies may be highly invasive to the patient. Disclosed herein are medical devices that may be used to deliver a medical device to a portion of the cardiovascular system in order to diagnose, treat, and/or repair the system. At least some of the medical devices disclosed herein may be used to deliver a replacement heart valve (e.g., a replacement aortic valve, replacement mitral valve, etc.). In addition, the devices disclosed herein may deliver the replacement heart valve percutaneously and, thus, may be much less invasive to the patient. The devices disclosed herein may also provide additional benefits as described in more detail below.

The figures illustrate selected components and/or arrangements of a medical device system 10, shown schematically in FIG. 1, for example. It should be noted that in any given figure, some features of the medical device system 10 may not be shown, or may be shown schematically, for simplicity. Additional details regarding some of the components of the medical device system 10 may be illustrated in other figures in greater detail.

The medical device system 10 may be used to deliver and/or deploy a variety of medical devices to a number of locations within the anatomy. In at least some embodiments, the medical device system 10 may include a replacement heart valve delivery system (e.g., a replacement aortic valve delivery system) that can be used for percutaneous delivery of a medical implant 16, such as a replacement/prosthetic heart valve. This, however, is not intended to be limiting as the medical device system 10 may also be used for other interventions including valve repair, valvuloplasty, delivery of an implantable medical device (e.g., such as a stent, graft, etc.), and the like, or other similar interventions.

The medical device system 10 may generally be described as a catheter system that includes an outer shaft 12, an inner shaft 14 (a portion of which is shown in FIG. 1) extending at least partially through a lumen of the outer shaft 12, and a medical implant 16 (e.g., a replacement heart valve implant) which may be coupled to the inner shaft 14 and disposed within an implant containment region 20 coupled to the outer shaft 12, the inner shaft 14 or both the outer shaft 12 and the inner shaft 14 during delivery of the medical implant 16. In some embodiments, a medical device handle 18 may be disposed at a proximal end of the outer shaft 12 and/or the inner shaft 14 and may include one or more actuation mechanisms associated therewith. In other words, a tubular member (e.g., the outer shaft 12, the inner shaft 14, etc.) may extend distally from the medical device handle 18. As will be described in greater detail below, the medical device handle 18 may be designed to manipulate the position of the outer shaft 12 relative to the inner shaft 14 and/or aid in the deployment of the medical implant 16.

In use, the medical device system 10 may be advanced percutaneously through the vasculature to a position adjacent to an area of interest and/or a treatment location. For example, in some embodiments, the medical device system 10 may be advanced through the vasculature to a position adjacent to a defective native valve (e.g., aortic valve, mitral valve, etc.). Alternative approaches to treat a defective aortic valve and/or other heart valve(s) are also contemplated with the medical device system 10. During delivery, the medical implant 16 may be generally disposed in an elongated and low profile “delivery” configuration within the implant containment region 20, as seen schematically in FIG. 1 for example. Once positioned, the outer shaft 12 and/or inner shaft 14 may be translated relative to each other and/or the medical implant 16 to expose (e.g., deploy) the medical implant 16. In some instances, a portion of the medical implant 16 may be self-expanding such that exposure of the medical implant 16 may deploy the medical implant 16. Alternatively, the medical implant 16 may be manipulated using the medical device handle 18 in order to translate the medical implant 16 into a deployed configuration suitable for implantation within the anatomy. When the medical implant 16 is suitably deployed within the anatomy, the medical device system 10 may be disconnected, detached, and/or released from the medical implant 16 and the medical device system 10 can be removed from the vasculature, leaving the medical implant 16 at the target tissue site.

As discussed above, the medical device system 10 may comprise an implant containment region 20 for accommodating the medical implant 16 in a collapsed form for introduction into the anatomy. The medical implant 16 may be a cardiac stent-valve. The delivery system 10 may be configured to permit delivery of the stent-valve 16 to a target site of implantation while the heart remains beating, for example, using a minimally invasive surgical and/or percutaneous procedure. In some embodiments, the delivery system 10 may be configured for introduction into the anatomical vascular system, and for advancement along the vasculature system to the desired site of implantation. For example, the delivery system 10 may be configured for introduction into the femoral artery, and guided retrograde via the descending aorta, aortic arch, and ascending aorta to the heart (sometimes called a transfemoral access). In other embodiments, the delivery system 10 may be insertable via the subclavian artery and guided retrograde to the heart (sometimes call transubclavian access). In other embodiments, the delivery system 10 may be inserted directly into a chamber of the heart such as a ventricle (for example, left ventricle) via a direct access route while the heart remains beating. For example, a direct access route may be through an aperture opened in the apex of the heart (sometimes called a transapical access).

It can be appreciated that during delivery and/or deployment of an implantable medical device (e.g., the medical implant 16), portions of the medical device system 10 may be required to be advanced through tortuous and/or narrow body lumens. Therefore, it may be desirable to utilize components and design medical delivery systems (e.g., such as the medical device system 10 and/or other medical devices) that reduce the profile of portions of the medical device while maintaining sufficient strength (compressive, torsional, etc.) and flexibility of the system as a whole.

In some examples, the stent-valve 16 may be expandable from a compressed or collapsed condition to an expanded condition, in order to anchor the stent-valve 16 at the implantation site. For example, the stent-valve 16 may form a friction and/or interference fit with respect to the native anatomy. Various shapes and geometries of stent-valve 16 may be used to fit the anatomy at the site of implantation. The stent-valve 16 may be self-expanding and/or may be configured to be expandable by an expandable member (for example, a balloon). Self-expanding stent-valves 16 may be constructed from shape-memory material, for example, a shape-memory metal alloy (e.g., nitinol). The self-expanding stent-valve 16 may be retained in its compressed state by being constrained within the containment region 20 of the delivery system 10. Upon at least partial release from the containment region 20, the released portion of the stent-valve 16 may be free to expand. Balloon expandable stent-valves 16 may also be made of shape-memory material, stainless steel, cobalt-chromium alloy or other materials. A non-limiting list of materials contemplated for one or more components of the stent delivery system 10 described herein is set forth below.

FIG. 2 illustrates an example first step in releasing (e.g., deploying) the stent-valve 16 from the medical device delivery system 10. As shown in FIG. 2, the containment region 20 of the medical device delivery system 10 may comprise a first sheath 22 and/or a second sheath 24. The first sheath 22 may be referred to as the distal sheath. The second sheath 24 may be referred to as the proximal sheath. Together, the first sheath 22 and the second sheath 24 may be translatable between a closed position (at least partially covering the stent-valve 16) and an open position (at least partially exposing at least a portion of the stent-valve 16). For example, FIG. 1 illustrates both the first sheath 22 and the second sheath 24 (collectively referred to as the containment region 20 above) in a closed position (wherein they are covering the stent-valve 16). Further, FIG. 2 illustrates that the first sheath 22 and the second sheath 24 may be translatable in opposite directions to an open position, as described above. For example, the first sheath 22 may be translatable in a distal direction (indicated by arrow 23 in FIG. 2) while the second sheath 24 may be translatable in a proximal direction (indicated by arrow 25 in FIG. 2).

Additionally, in some instances, the first sheath 22 and the second sheath 24 may translate independent of one another to release of the stent-valve 16 from the medical device delivery system 10. For example, FIG. 2 illustrates that translating the second sheath 24 in a proximal direction (e.g., indicated by arrow 25) while holding the first sheath 22 stationary, a portion 26 of the stent-valve 16 may be partially or fully released before a portion 28 of the stent-valve 16 covered by the first sheath 22 is partially or fully released. Further 3 illustrates that the portion 28 may subsequently be released by translation of the first sheath 22 in a distal direction (e.g., indicated by arrow 23).

Additionally, in some examples, the length of the second sheath 24 may be greater than the length of the first sheath 22. For example, the ratio of the second sheath 24 length divided by the first sheath 22 length may be at least 1.1, optionally at least 1.2, optionally at least 1.3, optionally at least 1.4, optionally at least 1.5, optionally at least 1.6, optionally at least 1.7, optionally at least 1.8, optionally at least 1.9, optionally at least 2.0, optionally at least 2.1, optionally at least 2.2, optionally at least 2.3, optionally at least 2.4, optionally at least 2.5, optionally at least 2.6, optionally at least 2.7, optionally at least 2.8, optionally at least 2.9, optionally at least 3, optionally at least 3.5, optionally at least 4 or optionally at least 4.5, or optionally at least 5.

FIG. 4 shows an enlarged portion of the distal region of the medical device delivery system 10 described above. For example, FIG. 4 illustrates the outer shaft 12 attached to the second (e.g., proximal) sheath 24 at a first connection point 30. Additionally, FIG. 4 illustrates the inner shaft 14 attached to a tip member 34 at a second connection region 32. Further, the tip member 34 may be attached to the first (e.g., distal) sheath 22. It can be appreciated that the tip member 34 may be designed with an atraumatic geometry, whereby the tip member 34 may include a tapered portion designed to ease navigation of the medical system 10 through challenging anatomical pathways. Additionally, FIG. 4 illustrates that the inner shaft 14 may include a lumen 36 through which a guidewire may be advanced.

It can be appreciated from FIG. 4 that as the outer shaft 12 translates with respect to the inner shaft 14, the second sheath 24 and the first sheath 22 will, correspondingly, translate with respect to one another. As will be described in greater detail below, as the outer shaft 12 and/or the inner shaft 14 are manipulated via the handle 18 (shown in FIG. 1), the second sheath 24 and/or the first sheath 22 may translate to release the medical implant 16.

FIG. 5 illustrates a cross-section of the handle 18 described above. The handle 18 may include a proximal end region 17 and a distal end region 19. FIG. 5 shows the outer shaft 12 (described above) and the inner shaft 14 (described above) entering the distal end region 19 of the handle 18. The outer shaft 12 may be coupled (e.g., attached) to a translation member 44. As shown in FIG. 5, the translation member 44 may be nested within a helical channel 46 disposed along a carriage 40. The carriage 40 may be coupled (e.g., attached) to a first actuator 38. It can be appreciated that the first actuator 38 may be designed to permit an operator to grasp and rotate the first actuator 38, whereby rotation of the first actuator 38 may correspondingly rotate the carriage 40. Further, rotation of the carriage 40 may rotate the helical channel 46, thereby causing the translation member 44 to translate parallel to the longitudinal axis of the handle 18. It can be appreciated that because the translation member 44 is attached to the outer shaft 12, translation of the translation member 44 will translate the outer shaft 12 correspondingly. Further, in some examples, the first actuator 38 may be designed to rotate in both a clockwise and a counterclockwise direction, thereby permitting an operator to selectively translate the outer shaft 12 in both a distal-to-proximal direction and also a proximal-to-distal direction.

Additionally, FIG. 5 illustrates that the handle 18 may include a second actuator 39 which is coupled to the inner shaft 14. Further, it can be appreciated the second actuator 39 may be coupled to the inner shaft 14 via a similar mechanism as described with respect to the first actuator 38. For example, the second actuator 39 may be coupled to the inner shaft 14 via a second translation member and second carriage 48. Further, rotation of the second actuator 39 (either in a clockwise or a counter-clockwise direction) may translate the inner shaft 14 in a distal-to-proximal direction or a proximal-to-distal direction (depending on the direction of rotation of the second actuator 39).

Further, as discussed above, because each of the outer shaft 12 and the inner shaft 14 are coupled to the second sheath 24 (not shown in FIG. 5, but described above) and the first sheath 22 (not shown in FIG. 5, but described above), manipulation of the first actuator 38 and/or the second actuator 39 may control the movement of the first sheath 22 and the second sheath 24 relative to one another. Additionally, it can be appreciated that it may be beneficial for either the first sheath 22 (not shown in FIG. 5, but described above) or the second sheath 24 (not shown in FIG. 5, but described above) to maintain its position while the second sheath 24 or the first sheath 22 is rotated. In other words, if an operator chooses to rotate the first actuator 38 (thereby translating the second sheath 24), the handle 18 may be designed such that the second carriage 48 resists any back-loading forces placed upon it by the translation of the second sheath 24 (and/or the deployment of the medical implant). Correspondingly, if the operator chooses to rotate the second actuator 39 (thereby translating the first sheath 22), the handle 18 may be designed such that the first carriage 40 resists any back-loading forces placed upon it by the translation of the first sheath 22 (and/or the deployment of the medical implant).

It can be appreciated, therefore, that, in some configurations, each of the first carriage 40 and second carriage 48 may need to be prevented from freely rotating (e.g., freely spinning) within the handle 18. In other words, it may be beneficial to design the handle 18 to include one or more components which impart a frictional resistance to the rotation of each of the first carriage 40 and the second carriage 48. It can be appreciated that this resistance may be translated to the first actuator 38 and the second actuator 39, thereby requiring an operator to overcome the resistive force in order to rotate either of the first actuator 38 and the second actuator 39. However, this resistance may provide increased control as an operator rotates either of the first actuator 38 and the second actuator 39 (when deploying the medical implant, for example).

To that end, FIG. 5 shows that the handle 18 may include a housing 42 positioned overtop the first carriage 40. In other words, the first carriage 40 may rotate inside an inner cavity of the housing 42. Further, FIG. 5 illustrates a cap 50 positioned along the distal end region of the handle 18. Specifically, the cap 50 may extend into the distal end of the inner cavity of the housing 42 and also into at least a portion of the distal end region of the first carriage 40. Additionally, FIG. 5 illustrates that the handle 18 may include a resistance member 66 (e.g., gasket, rubber gasket, etc.) positioned along the proximal end region of the cap 50. The resistance member 66 may exert an outward radial force upon the carriage 40, thereby imparting a resistive force (as described above) to the rotation of the first carriage 40. In other words, in order to rotate the first actuator 38, an operator may have to overcome the radially outward force the resistance member 66 imparts onto the first carriage 40.

While not shown in the figures, in some examples the medical device system 10 may include a third shaft (not shown for simplicity). The third shaft may be referred to as a “middle” shaft in some examples. The third shaft may be positioned between the inner shaft 14 and the outer shaft 12. Further, the third shaft may extend from the handle 18 to a positioned adjacent the stent-valve 16 (described above). In some examples, the stent-valve 16 may be coupled to the third shaft. For example, the stent-valve 16 may be coupled to the third shaft via a stent-valve holder (not shown in the figures). Additionally, the third shaft may be stationary with respect to the outer shaft 12, the inner shaft 14 or both the outer shaft 12 and the inner shaft 14. In other words, as the outer shaft 12 and/or the inner shaft 14 are actuated (as described above), the third shaft may remain stationary relative thereto. It can be appreciated that the third shaft may provide a stable, stationary “platform” on which to mount the stent-valve 16. For example, as the first sheath 22 and/or the second sheath 24 are translating with respect to one another (and the stent-valve 16), the third shaft may prevent the stent-valve 16 from sliding (e.g., dragging) as the first sheath 22 and/or the second sheath 24 are translated.

In some examples, the third shaft (described above) may be coupled to an inner spine tube 70 (shown in FIG. 5). The inner spine tube 70 may be coupled to the housing 42 via a screw 68. It can be appreciated that the inner spine tube 70 and/or the housing 42 may remain stationary as the outer shaft 12 and/or the inner shaft 14 are actuated by the first actuator 38 and the second actuator 39, respectively.

FIG. 6 shows a perspective view of the cap 50 described above. The cap 50 may include a proximal end region 52, a distal end region 54 and a medial region 64 extending therebetween. Further, the cap 50 may include a lumen 56 extending from the proximal end region 52 to the distal end region 54. FIG. 6 further illustrates that the cap 50 may include a groove 58 (e.g., channel, etc.) positioned along the proximal end region 52 of the cap 50. The groove 58 may extend circumferentially around the outer surface of the cap 50. As will be shown in greater detail in FIG. 7, the groove 58 may extend radially inward from an outer surface of the cap 50. Further, the groove 58 may be sized to accept the resistance member 66 (not shown in FIG. 6, but described above).

FIG. 6 further illustrates that the cap 50 may include an aperture 60 positioned within the medial region 64 of the cap 50. The aperture 60 may include a length “L.” In some examples, the aperture may extend longitudinally along the medial region 64. Additionally, the cap 50 may include a lip 62 positioned along the distal end region 54 of the cap 50. The lip 62 may extend circumferentially around and extend radially away from the outer surface of the cap 50. In some examples, the lip 62 may include one or more tapered and/or curved surfaces 63.

FIG. 7 illustrates a cross section of the cap 50 shown in FIG. 6. For example, FIG. 7 illustrates the groove 58 positioned along the proximal end region 52 of the cap 50. Further, FIG. 7 illustrates that the cap may include a wall thickness “Y” extending between the outer surface 61 and the inner surface 65 of the medial region 64. As shown in FIG. 7, the groove 58 may extend only partially into the wall thickness “Y” of the cap 50.

Additionally, FIG. 7 illustrates the aperture 60 having a length “L” as described above. As shown in FIG. 7, the aperture 60 may extend entirely through the wall thickness “Y” of the cap 50. However, this is not intended to be limiting. Rather, in some examples, the aperture may extend only partially through the wall thickness “Y” of the cap 50. Further, FIG. 7 illustrates the lip 62 extending radially outward from the outer surface 61 of the cap 50. As discussed above, the lip 62 may include one or more tapered and/or curved surfaces 63.

While the resistive force imparted by the resistance member 66 (described above) may provide increased control for an operator when deploying the medical implant, in some instances it may be desirable to selectively remove the resistive force imparted by the resistance member 66 on the second sheath 24 (via the connection of the first carriage 40 and the outer shaft 12). Removing the resistive force may permit the second sheath 24 to more freely translate relative to the first sheath 22.

For example, in some instances it may be desirable for an operator to engage (e.g., load) the medical implant into the first sheath 22 and/or the second sheath 24. Further, in order to properly position the implant within the first sheath 22 and/or the second sheath 24, the operator may be required to manipulate the first sheath 22 and/or the second sheath 24 relative to one another. It can be appreciated that loading the implant into the first sheath 22 and/or the second sheath 24 may require an operator to manipulate the first actuator 38 and/or the second actuator 39 at the handle (in order to adjust the spacing and position of the first sheath 22 and/or the second sheath 24 relative to one another). It can be appreciated that this may require the operator to physically move between the handle (at one end of the medical device system 10) and the first and second sheaths 22, 24 (at the opposite end of the medical device system 10). Therefore, it may be desirable to design the handle 18 such that an operator can selectively remove the resistive force imparted to the first actuator 38 (and subsequently the second sheath 24 via the carriage 40 and outer shaft 12). In other words, when the operator is loading the stent-valve, the resistive force may be removed, and subsequently, after loading (e.g., during insertion of the medical device system 10 into a patient's body) and/or when the operator is deploying the stent-valve, the resistive force may be applied.

To that end, FIG. 8 illustrates a detailed view of the distal end region 19 of the medical device system 10 in a “pre-deployment” configuration. The pre-deployment configuration may represent a configuration which is designed to load the stent-valve into the first sheath 22 and/or the second sheath 24 (e.g., a configuration in which an operator can manipulate the second sheath 24 without having to use the handle 18).

FIG. 8 illustrates that the cap 50 (described above) has been shifted in a distal direction a distance “X.” Further, FIG. 8 illustrates that shifting the cap 50 in a distal direction may correspondingly shift the resistance member 66 in a distal direction a distance “X.” Specifically, shifting the cap 50 in a distal direction may shift the resistance member 66 to a position in which it is free from (e.g., not contacting) the inner surface 74 of the first carriage 40. As shown in FIG. 8, the resistance member 66 is positioned adjacent to an inner surface 67 of the housing 42, thereby removing the resistive force from the carriage 40.

FIG. 8 further illustrates that the handle 18 may include a screw 68 which is positioned at least partially within the aperture 60 of the cap 50. It can be appreciated that the screw 68 may be prevent the cap from sliding all the way out the distal end of the housing 42. Additionally, it can be appreciated that the length of the aperture 60 (described as length “L” in FIG. 6 and FIG. 7 corresponds to the distance “X” the cap shifts in the distal direction.

FIG. 9 illustrates a detailed view of the distal end region 19 of the medical device system 10 in a “deployment” configuration. The deployment configuration may represent a configuration which is designed to advance the system through a blood vessel and/or deploy the medical implant at a target site, for example. FIG. 9 illustrates that the cap 50 (described above) has been shifted in a proximal direction (shown by the arrows 72) such that the resistance member 66 contacts the inner surface 74 of the carriage 40. As described above, in this configuration, the resistance member 66 may exert a radially outward force upon the inner surface 74 of the carriage 40, which, in turn, imparts a resistive force on the first actuator 38 (not shown in FIG. 9) and the second sheath 24 (not shown in FIG. 9).

FIG. 9 further illustrates that the lip 62 of the cap 50 may be shifted proximally such that it contacts the distal end of the housing 42. It can be appreciated that the lip 62 may be designed to permit an operator to engage a portion thereof, which may permit the operator to more easily shift the cap 50 between the pre-deployment configuration and the deployment configuration. Further, the lip 62 may have a profile (e.g., a beveled edge) that sits flush with the housing 42, in order to reduce the exposed profile of the cap 50. This feature may reduce the risk of the cap 50 being moved accidentally out of the proximal position (after the cap 50 has been placed in the proximal position for implanting a loaded stent-valve 16).

FIG. 10 illustrates another example cap 150. The cap 150 may be similar in form and function to the cap 50. For example, FIG. 10 shows that the cap 150 may include an aperture 160 positioned in the medial region 164 of the cap 150. However, as illustrated in FIG. 10, the aperture 160 may be offset from the longitudinal axis 155 of the cap 150. It can be appreciated that offsetting the aperture 160 from the longitudinal axis 155 of the cap 150 may allow the resistance member to be shifted between the pre-deployment configuration and the deployment configuration via “rotating” the cap 150. In other words, instead of requiring an operator to slide the cap 150 linearly along the longitudinal axis (as described in FIG. 8 and FIG. 9), the cap configuration shown in FIG. 10 may allow the resistance member 66 shift longitudinally as the cap 150 is being rotated.

As discussed above, in some instances it may be desirable for an operator to engage (e.g., load) a medical implant into the first sheath 22 and/or the second sheath 24. Further, in order to properly load a medical implant within the first sheath 22 and/or the second sheath 24, the operator may be required to manipulate (e.g., shift) the first sheath 22 and/or the second sheath 24 relative to one another. Therefore, in some instances, it may be beneficial for an operator to use a medical implant loading device (e.g., stent-valve loader) to help advance the first sheath 22 and/or the second sheath 24 relative to one another to cover and contain a medical implant within the first sheath 22 and/or the second sheath 24.

FIG. 11 illustrates an example medical implant loading device 80. The medical implant loading device 80 may be utilized by an operator to load a stent-valve 16 (shown above) into the first sheath 22 and/or the second sheath 24 prior to performing a medical procedure. FIG. 11 illustrates the medical implant loading device 80 in a configuration in which the medical implant 16 has already been loaded within the medical implant loading device 80. In other words, the first sheath 22, the second sheath 24 and the medical implant 16 are not visible in FIG. 11 (as they are positioned within the medical implant loading device 80).

However, FIG. 11 does illustrate that the medical implant loading device 80 may include a knob 82 coupled to a stem 84. FIG. 11 further illustrates the outer shaft 12 (described above) extending into the stem 84. Additionally, FIG. 11 shows that the implant loading device may include a sleeve 86 (visible through an aperture located in the stem 84). As will be described in greater detail below, it can be appreciated that the knob 82 may be rotated with respect to the stem 84. Rotation of the knob 82 with respect to the stem 84 may translate the first sheath 22 (described above) longitudinally with respect to the second sheath 24 (described above).

FIG. 12 illustrates an exploded view of the medical implant loading device 80 described above. For example, FIG. 12 illustrates the knob 82 and the stem 84. Further, FIG. 12 illustrates that the stem 84 may include a threaded portion 85 positioned along an end region thereof. As will be described in greater detail with respect to FIG. 13 below, the threaded portion 85 may be utilized to couple the knob 82 with the stem 84.

FIG. 12 further illustrates the sleeve 86 described above. As shown in FIG. 12, the sleeve 86 may separate into a first sleeve portion 87 a and a second sleeve portion 87 b. The first sleeve portion 87 a and the second sleeve portion 87 b may engage with one another in a “clamshell” configuration to form sleeve 86. The sleeve 86 may include proximal end region 91 and a distal end region 93. Additionally, FIG. 12 shows the outer shaft 12 extending through the stem 84. It can be appreciated that the stem 84 may be slid onto and overtop the first sheath 22 and the second sheath 24 such that the stem 84 is positioned proximal to the second sheath 24. Additionally, the sleeve 86 may be positioned within portion of an interior cavity of the stem 84 and/or the knob 82.

As described above, FIG. 12 further illustrates the outer shaft 12 coupled to the second sheath 24. In some examples, the distal end region of the outer shaft 12 may include a tapered region 92. The tapered region 92 may extend from the distal end region of the outer shaft 12 to the proximal end of the second sheath 24. Additionally, FIG. 12 illustrates the tip member 34 (described above) extending into an extension member 90. The extension member 90 may extend in a proximal-to-distal direction from the tip member 34.

As discussed above, the medical implant loading device 80 may be utilized to load a medical device (e.g., a stent-valve) into the first sheath 22 and/or the second sheath 24. The medical implant loading device 80 may be configured to apply an axial force to the first sheath 22 and/or the second sheath 24 as part of the loading operation. These axial forces may be designed to urge movement of the first sheath 22 and/or the second sheath 24 toward one another to cover all, or a portion of, the stent-valve 16. As discussed above, it can be appreciated that the ability to release the resistance of the first actuator 38 and/or the second actuator 39 (described above) within the handle (for example, by moving the cap 50 to its distal position as described above) may allow the first actuator 38 and/or the second actuator 39 to move freely as the knob 82 and/or the stem 84 are rotated (and, therefore, axially translated) with respect to one another. It can be appreciated that permitting the first actuator 38 and/or the second actuator 39 to move freely as the knob 82 shifts relative to the stem 84 may facilitate the loading of the stent-valve 16 (illustrated in FIGS. 1-4) by permitting the operator to remain at the distal end of the catheter, rather than having to physically move repeatedly between the handle and the distal end of the catheter to “mirror” the relative movement of the first sheath 22 and the second sheath 24 with the first actuator 38 and the second actuator 39.

FIG. 13 illustrates a cross-section of the medical implant loading device 80. For simplicity, FIG. 13 does not show a medical implant positioned between the first sheath 22 and the second sheath 24. However, it can be appreciated that an operator may position the medical implant (e.g., a stent-valve 16) between the first sheath 22 and the second sheath 24 prior to moving the first sheath 22 relative to the second sheath 24 via the medical implant loading device 80. As described above, in some instances the medical implant may be coupled to a third shaft (described above), whereby the third shaft may extend between the first sheath 22 and the second sheath 24.

It can be appreciated from FIG. 13 that rotation of the knob 82 may apply a proximally-directed force to the first sheath 22 (via the extension member 90). For example, the knob 82 may include an inner surface profile which engages the extension member 90. Further, FIG. 13 illustrates that the knob 82 may include a threaded portion 89 designed to mate with the threaded portion 85 along the distal end region of the stem 84.

FIG. 13 shows that the extension member 90 may abut (directly or indirectly) the tip member 34 (or any other member attached to the tip member 34) of the first sheath 22. Further, it can be appreciated from FIG. 13 that rotation of the stem 84 may apply a distally-directed force to the second sheath 24 via sleeve 86. FIG. 13 illustrates that the sleeve 86 (including the first sleeve portion 87 a and the second sleeve portion 87 b) may be positioned within the stem 84. Further, the second sheath 24 and all (or a portion of) the first sheath 22 may be positioned within the sleeve 86. Additionally, FIG. 13 illustrates that the distal end region 91 of the sleeve 86 may include a (e.g. tapered) surface which engages the tapered portion 92 of the outer shaft 12.

As described above, an operator may rotate either the knob 82 and/or the stem 84 to progressively apply an axially compressive force between the knob 82 and the stem 84 to move the first sheath 22 and/or the second sheath 24 closer toward one another. This may permit an operator to load a stent-valve into the first sheath 22 and/or the second sheath 24 while working primarily at the distal end of the catheter. The medical implant loading device 80 may apply the axial forces at the distal end to close the first sheath 22 and/or the second sheath 24 over the stent valve as part of the loading operation. As described above, it can be appreciated that the ability to release the resistance of the first actuator 38 and/or the second actuator 39 within the handle 18 (by shifting the cap 50 to its distal position, for example) and may improve the speed and efficiency in which an operator may load a medical implant prior to performing a medical procedure.

The materials that can be used for the various components of the medical devices and/or systems disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to the medical device delivery system 10 including the various components of the medical device delivery system 10.

The medical device delivery system 10 may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), high density polyethylene (HDPE), polyester, Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), ultra-high molecular weight (UHMW) polyethylene, polypropylene, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. In some embodiments the sheath can be blended with a liquid crystal polymer (LCP).

Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any other suitable material.

In at least some embodiments, portions or all of the medical device delivery system 10 may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user of the shaft in determining its location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of the medical device delivery system 10 to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted into the shaft. For example, the medical device delivery system 10 may include a material that does not substantially distort the image and create substantial artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. The medical device delivery system 10 may also be made from a material that the MRI machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nitinol, and the like, and others.

It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the disclosure. This may include, to the extent that it is appropriate, the use of any of the features of one example embodiment being used in other embodiments. The disclosure's scope is, of course, defined in the language in which the appended claims are expressed. 

What is claimed is:
 1. A delivery system for an implantable medical device, comprising: an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween; a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing; a cap coupled to the handle; and a resistance member disposed along a portion of the cap; wherein the cap is configured to shift between a first configuration and a deployment configuration, and wherein the carriage is free from the resistance member in the first configuration and wherein the resistance member contacts the carriage in the deployment configuration.
 2. The delivery system of claim 2, wherein the resistance member contacts an inner surface along a distal end region of the housing in the first configuration.
 3. The delivery system of claim 3, wherein the resistance member contacts an inner surface along a distal end region of the carriage in the deployment configuration.
 4. The delivery system of claim 1, wherein the carriage is configured to rotate, and wherein the resistance member is configured to increase a rotational force required to rotate the carriage in the deployment configuration.
 5. The delivery system of claim 1, wherein the cap includes a circumferential groove positioned along a proximal end region thereof, wherein at least a portion of the resistance member is positioned along the groove.
 6. The delivery system of claim 1, further comprising an implant loading device positioned adjacent the distal end region of the outer shaft.
 7. The delivery system of claim 6, wherein the cap includes an inner surface, an outer surface and a wall extending therebetween, and wherein the cap includes an aperture extending through a wall of the cap.
 8. The delivery system of claim 7, wherein the aperture includes a length, and wherein the length of the aperture corresponds to a distance along which the cap shifts between the first configuration and the deployment configuration.
 9. The delivery system of claim 7, wherein the aperture is aligned along a longitudinal axis of the cap.
 10. The delivery system of claim 7, wherein the aperture is offset from a longitudinal axis of the cap.
 11. The delivery system of claim 10, wherein rotating the cap shifts it between the first configuration and the deployment configuration.
 12. The delivery system of claim 1, wherein the cap includes a circumferential lip extending circumferentially along a distal end region thereof.
 13. The delivery system of claim 12, wherein the lip extends radially away from an outer surface of the cap.
 14. The delivery system of claim 1, wherein the resistance member is configured to exert a radially outward force on an inner surface of the carriage in the deployment configuration.
 15. A delivery system for an implantable medical device, comprising: an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween; a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing; a cap coupled to the handle; and a resistance member disposed along a portion of the cap; wherein the cap is configured to shift between a first configuration and a deployment configuration, and wherein the carriage is free from the resistance member in the first configuration and wherein the resistance member exerts a radially outward force upon the carriage in the deployment configuration.
 16. The delivery system of claim 15, wherein the resistance member contacts an inner surface along a distal end region of the housing in the first configuration.
 17. The delivery system of claim 16, wherein the resistance member contacts an inner surface along a distal end region of the carriage in the deployment configuration.
 18. The delivery system of claim 15, wherein the carriage is configured to rotate, and wherein the resistance member is configured to increase a rotational force required to rotate the carriage in the deployment configuration.
 19. A method of manufacturing an implantable medical device, the method comprising: engaging the implantable medical device with a medical device delivery system in a pre-deployment configuration, the medical device delivery system including: an outer shaft having a distal end region, a proximal end region and a lumen extending therebetween; a handle coupled to the proximal end region of the outer shaft, wherein the handle includes a first actuator, a carriage and a housing; a cap coupled to the handle; and a resistance member disposed along a portion of the cap; converting the medical device delivery system from a pre-deployment configuration to a deployment configuration, wherein converting the medical device delivery system includes shifting the cap from a first position to a second position, wherein the carriage is free from the resistance member when the cap is in the first position and wherein the resistance member contacts the carriage when the cap is in the second position.
 20. The method of claim 20, wherein the implantable medical device includes an implantable heart valve. 